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  <div class="section" id="numpy-seterrcall">
<h1>numpy.seterrcall<a class="headerlink" href="#numpy-seterrcall" title="Permalink to this headline">¶</a></h1>
<dl class="function">
<dt id="numpy.seterrcall">
<code class="sig-prename descclassname">numpy.</code><code class="sig-name descname">seterrcall</code><span class="sig-paren">(</span><em class="sig-param">func</em><span class="sig-paren">)</span><a class="reference external" href="https://github.com/numpy/numpy/blob/v1.18.1/numpy/core/_ufunc_config.py#L229-L319"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#numpy.seterrcall" title="Permalink to this definition">¶</a></dt>
<dd><p>Set the floating-point error callback function or log object.</p>
<p>There are two ways to capture floating-point error messages.  The first
is to set the error-handler to ‘call’, using <a class="reference internal" href="numpy.seterr.html#numpy.seterr" title="numpy.seterr"><code class="xref py py-obj docutils literal notranslate"><span class="pre">seterr</span></code></a>.  Then, set
the function to call using this function.</p>
<p>The second is to set the error-handler to ‘log’, using <a class="reference internal" href="numpy.seterr.html#numpy.seterr" title="numpy.seterr"><code class="xref py py-obj docutils literal notranslate"><span class="pre">seterr</span></code></a>.
Floating-point errors then trigger a call to the ‘write’ method of
the provided object.</p>
<dl class="field-list">
<dt class="field-odd">Parameters</dt>
<dd class="field-odd"><dl>
<dt><strong>func</strong><span class="classifier">callable f(err, flag) or object with write method</span></dt><dd><p>Function to call upon floating-point errors (‘call’-mode) or
object whose ‘write’ method is used to log such message (‘log’-mode).</p>
<p>The call function takes two arguments. The first is a string describing
the type of error (such as “divide by zero”, “overflow”, “underflow”,
or “invalid value”), and the second is the status flag.  The flag is a
byte, whose four least-significant bits indicate the type of error, one
of “divide”, “over”, “under”, “invalid”:</p>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">[</span><span class="mi">0</span> <span class="mi">0</span> <span class="mi">0</span> <span class="mi">0</span> <span class="n">divide</span> <span class="n">over</span> <span class="n">under</span> <span class="n">invalid</span><span class="p">]</span>
</pre></div>
</div>
<p>In other words, <code class="docutils literal notranslate"><span class="pre">flags</span> <span class="pre">=</span> <span class="pre">divide</span> <span class="pre">+</span> <span class="pre">2*over</span> <span class="pre">+</span> <span class="pre">4*under</span> <span class="pre">+</span> <span class="pre">8*invalid</span></code>.</p>
<p>If an object is provided, its write method should take one argument,
a string.</p>
</dd>
</dl>
</dd>
<dt class="field-even">Returns</dt>
<dd class="field-even"><dl class="simple">
<dt><strong>h</strong><span class="classifier">callable, log instance or None</span></dt><dd><p>The old error handler.</p>
</dd>
</dl>
</dd>
</dl>
<div class="admonition seealso">
<p class="admonition-title">See also</p>
<p><a class="reference internal" href="numpy.seterr.html#numpy.seterr" title="numpy.seterr"><code class="xref py py-obj docutils literal notranslate"><span class="pre">seterr</span></code></a>, <a class="reference internal" href="numpy.geterr.html#numpy.geterr" title="numpy.geterr"><code class="xref py py-obj docutils literal notranslate"><span class="pre">geterr</span></code></a>, <a class="reference internal" href="numpy.geterrcall.html#numpy.geterrcall" title="numpy.geterrcall"><code class="xref py py-obj docutils literal notranslate"><span class="pre">geterrcall</span></code></a></p>
</div>
<p class="rubric">Examples</p>
<p>Callback upon error:</p>
<div class="doctest highlight-default notranslate"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="k">def</span> <span class="nf">err_handler</span><span class="p">(</span><span class="nb">type</span><span class="p">,</span> <span class="n">flag</span><span class="p">):</span>
<span class="gp">... </span>    <span class="nb">print</span><span class="p">(</span><span class="s2">&quot;Floating point error (</span><span class="si">%s</span><span class="s2">), with flag </span><span class="si">%s</span><span class="s2">&quot;</span> <span class="o">%</span> <span class="p">(</span><span class="nb">type</span><span class="p">,</span> <span class="n">flag</span><span class="p">))</span>
<span class="gp">...</span>
</pre></div>
</div>
<div class="doctest highlight-default notranslate"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">saved_handler</span> <span class="o">=</span> <span class="n">np</span><span class="o">.</span><span class="n">seterrcall</span><span class="p">(</span><span class="n">err_handler</span><span class="p">)</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">save_err</span> <span class="o">=</span> <span class="n">np</span><span class="o">.</span><span class="n">seterr</span><span class="p">(</span><span class="nb">all</span><span class="o">=</span><span class="s1">&#39;call&#39;</span><span class="p">)</span>
<span class="gp">&gt;&gt;&gt; </span><span class="kn">from</span> <span class="nn">collections</span> <span class="kn">import</span> <span class="n">OrderedDict</span>
</pre></div>
</div>
<div class="doctest highlight-default notranslate"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">np</span><span class="o">.</span><span class="n">array</span><span class="p">([</span><span class="mi">1</span><span class="p">,</span> <span class="mi">2</span><span class="p">,</span> <span class="mi">3</span><span class="p">])</span> <span class="o">/</span> <span class="mf">0.0</span>
<span class="go">Floating point error (divide by zero), with flag 1</span>
<span class="go">array([inf, inf, inf])</span>
</pre></div>
</div>
<div class="doctest highlight-default notranslate"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">np</span><span class="o">.</span><span class="n">seterrcall</span><span class="p">(</span><span class="n">saved_handler</span><span class="p">)</span>
<span class="go">&lt;function err_handler at 0x...&gt;</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">OrderedDict</span><span class="p">(</span><span class="nb">sorted</span><span class="p">(</span><span class="n">np</span><span class="o">.</span><span class="n">seterr</span><span class="p">(</span><span class="o">**</span><span class="n">save_err</span><span class="p">)</span><span class="o">.</span><span class="n">items</span><span class="p">()))</span>
<span class="go">OrderedDict([(&#39;divide&#39;, &#39;call&#39;), (&#39;invalid&#39;, &#39;call&#39;), (&#39;over&#39;, &#39;call&#39;), (&#39;under&#39;, &#39;call&#39;)])</span>
</pre></div>
</div>
<p>Log error message:</p>
<div class="doctest highlight-default notranslate"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="k">class</span> <span class="nc">Log</span><span class="p">(</span><span class="nb">object</span><span class="p">):</span>
<span class="gp">... </span>    <span class="k">def</span> <span class="nf">write</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">msg</span><span class="p">):</span>
<span class="gp">... </span>        <span class="nb">print</span><span class="p">(</span><span class="s2">&quot;LOG: </span><span class="si">%s</span><span class="s2">&quot;</span> <span class="o">%</span> <span class="n">msg</span><span class="p">)</span>
<span class="gp">...</span>
</pre></div>
</div>
<div class="doctest highlight-default notranslate"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">log</span> <span class="o">=</span> <span class="n">Log</span><span class="p">()</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">saved_handler</span> <span class="o">=</span> <span class="n">np</span><span class="o">.</span><span class="n">seterrcall</span><span class="p">(</span><span class="n">log</span><span class="p">)</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">save_err</span> <span class="o">=</span> <span class="n">np</span><span class="o">.</span><span class="n">seterr</span><span class="p">(</span><span class="nb">all</span><span class="o">=</span><span class="s1">&#39;log&#39;</span><span class="p">)</span>
</pre></div>
</div>
<div class="doctest highlight-default notranslate"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">np</span><span class="o">.</span><span class="n">array</span><span class="p">([</span><span class="mi">1</span><span class="p">,</span> <span class="mi">2</span><span class="p">,</span> <span class="mi">3</span><span class="p">])</span> <span class="o">/</span> <span class="mf">0.0</span>
<span class="go">LOG: Warning: divide by zero encountered in true_divide</span>
<span class="go">array([inf, inf, inf])</span>
</pre></div>
</div>
<div class="doctest highlight-default notranslate"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">np</span><span class="o">.</span><span class="n">seterrcall</span><span class="p">(</span><span class="n">saved_handler</span><span class="p">)</span>
<span class="go">&lt;numpy.core.numeric.Log object at 0x...&gt;</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">OrderedDict</span><span class="p">(</span><span class="nb">sorted</span><span class="p">(</span><span class="n">np</span><span class="o">.</span><span class="n">seterr</span><span class="p">(</span><span class="o">**</span><span class="n">save_err</span><span class="p">)</span><span class="o">.</span><span class="n">items</span><span class="p">()))</span>
<span class="go">OrderedDict([(&#39;divide&#39;, &#39;log&#39;), (&#39;invalid&#39;, &#39;log&#39;), (&#39;over&#39;, &#39;log&#39;), (&#39;under&#39;, &#39;log&#39;)])</span>
</pre></div>
</div>
</dd></dl>

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